Vertical-Collection: Allowing non-fixed width columns

[alexander-alvarez]

#483 Introduced vertical collection, but had the requirement to specify the width of every column, because otherwise headers and body can get out of sync.

• Should find an elegant solution where column widths match between header, footer, and body
• If the table resizes, then the columns in the different tables should still be aligned

Should evaluate if the solution plays well with horizontal scrolling (and scrolling both headers and footers with one scrollbar)